1. Field of the Invention
The present invention relates to an insulation type switching power source apparatus.
2. Description of Related Art
Conventionally, an insulation type switching power source, which insulates a primary circuit system and a secondary circuit system from each other and generates a desired output voltage from an input voltage, is used for various electronic apparatuses.
In the meantime, as prior art examples relevant to the above description, there are JP-A-2013-62947 and JP-A-2005-261128.
Generally, an insulation type switching power source apparatus has a structure (SSR [secondary side regulator] system) which uses a photocoupler to perform output feedback control. However, the conventional structure using a photocoupler has problems of long-term reliability deterioration and cost increase due to increase in the number of components.
Besides, conventionally, also an insulation type switching power source apparatus is proposed, which does not use a photocoupler but uses an auxiliary winding or primary winding of a transformer to perform output feedback control (PSR [primary side regulator] system). However, in the conventional structure that uses an auxiliary winding or a primary winding, there is room for further improvement as to accuracy of the output feedback control.